I made this today out of a £2 solar table light, took the solar cell out and added a extender wire so the lamp's next to my bed, the solar panels stuck on my window. I also reduced the brightness of the LED by adding a resistor. Free night light!!!
I made a Joule Thief out of an old disposable camera today, basically a circuit that'll run an 3 volt torch LED from a single AA/AAA battery for weeks. Need to wait to get some prototype strip board off ebay and I'm going to pop one in my lamp.
Read today that a bloke had one running off a single AA for 4 months.